Diarrhoea-related morbidity and rotavirus infection in France

The perpetuation and epidemic recurrence of communicable diseases in human populations

Recurrence of communicable diseases is a looming threat for human populations. Factors explaining the recurrences are partially known, involving demographics, biology, and complex relationships with the environment, but no comprehensive theory exists today. Here, we review some recent results obtained in modelling studies with a view to understanding better the mechanisms of perpetuation. Factors intrinsic to the interaction of pathogen and host have regained interest in this respect, especially with multiple pathogen and multiple population interactions. Extrinsic factors, including pure demography and environmental forcing are also strong predictors. With increasingly detailed data available, large-scale integrated models will help sorting out the multiple influences on recurrence. To cite this article: P.-Y. Boëlle, C. R. Biologies 330 (2007).

The paediatric burden of rotavirus disease in Europe

Rotaviruses are a major cause of hospitalizations for acute gastroenteritis in developed countries. This review shows the burden of rotavirus disease in < 5-year-old children in Europe. An estimated 72,000-77,000 hospitalizations for community-acquired rotavirus disease occur annually in the 23 million under-fives living in the European Union (EU-25), with a median cost of Euro 1417 per case. Annual hospitalization incidence rates range from 0.3 to 11.9/1000 children < 5 years old (median 3/1000). The median proportion of hospital-acquired rotavirus disease among all cases of hospitalization for rotavirus disease is estimated to be 21%. Countries of the EU-25 require information on the burden of rotavirus disease to support introduction of rotavirus vaccines. Data on cases treated at home, medical visits, and emergency wards as well as rotavirus-associated deaths are limited. To fully evaluate the impact and effectiveness of rotavirus vaccination programmes in Europe, additional epidemiological studies will be critical and desirable.

[Morbidity and cost of rotavirus infections in France]

BACKGROUND

Rotavirus is the most common cause of severe diarrhea in children. Morbidity and mortality related to rotavirus infection is not well known in temperate countries in general, and in France in particular.

OBJECTIVES

The aim of this study was estimate the morbidity, mortality, and cost related to the rotavirus infection in France, in order to assess the potential impact of a vaccination program.

METHODS

A birth cohort was followed until 5 years of age using a decision tree model. Rotavirus infection incidence rates were modeled according to age, seasons, and breast-feeding status.

RESULTS

Based on estimates from a decision model, we found that in France, rotavirus infection was responsible for 300,000 annual episodes of acute diarrhea, 138,000 visits to general practitioners, 18,000 hospitalizations, and 9 deaths. The annual direct cost related to rotavirus infection care was estimated at 28 million euros.

CONCLUSION

This study demonstrates the high morbidity and cost of care associated with rotavirus infection in France. The decision tree model developed in this study could be used in the future to estimate the potential effectiveness, cost and cost-effectiveness of childhood vaccination strategies using new rotavirus vaccines.

Infection nosocomiale à rotavirus en pédiatrie générale. Enquête d’observation multicentrique

OBJECTIVE

Rotavirus nosocomial infection (RNI) is frequent in pediatric units. This study was designed to determine the incidence and the main risk factors of RNI in children aged 3 months-3 years and admitted for at least 48 hours days during the epidemic period.

PATIENTS AND METHODS

A stool sample was obtained within the 24 hours of admission. An additional sample was collected from rotavirus-negative children either the day of discharge, or when they developed abnormal clinical signs. Parents were contacted by phone after discharge. Children initially rotavirus-negative and positive 2 days or more after admission were considered as certain nosocomial cases. In the absence of the second sample, possible nosocomial cases were considered if new symptoms (i.e.; fever and or digestive symptoms) occurred 2 days or more after the first negative sample.

RESULTS

One hundred and seventeen children were included. The incidence was 11.1% for certain NRI, 16.8% for possible hospital-acquired cases and 19.4% for the whole cases. Possible risk factors were the low number of nurses during the weekend, the great number of medicine students in the unit, and no use of individual material.

CONCLUSION

NRI have a high incidence, whose reality can only be approximated by taking into account the possible NRI occurring at home after hospital-discharge.

Le poids médico-économique des gastro-entérites aiguës de l’enfant : l’éclairage du Programme de Médicalisation des Systèmes d’Information (PMSI)

OBJECTIVES

To estimate the burden of hospitalized infectious gastroenteritis of children younger than 5 years of age and associated costs.

METHODS

We analyzed 1997 hospital discharges with a primary diagnosis of gastroenteritis or a secondary diagnosis of gastroenteritis with gastroenteritis symptoms or complications as primary diagnosis and compared the deaths with those of the national mortality data.

RESULTS

Gastroenteritis was associated with 51,125 hospitalizations which accounted for 11.4% of hospitalization discharges for this age group and an annual rate of 1,385 per 100,000 children <5-year-old. Most gastroenteritis (56%) were registered as "probably infectious", 36% as "viral" (43% of which were coded "rotavirus") and 8% as "bacterial" (of which 60% were coded "Salmonella"). The seasonal peak was winter for rotaviral, viral and "probably infectious" gastroenteritis, summer for those related to salmonellosis. Incidence increased inversely with age: 3606/100,000 infants <1-year-old, 257/100,000 4-year-old children. Complications (especially dehydration) were observed in 21% of viral gastroenteritis and 17% of bacterial gastroenteritis. At least, 14 deaths were found in both hospital discharge and mortality data. The mean duration of stay (3.2 days) was significantly higher in infants <1-year-old, viral etiology, association with complications or bronchiolitis. The costs of hospitalization could be estimated to 62 million Euros.

DISCUSSION

Our results are similar to those obtained in other developed countries. Despite variations in encoding the discharge reports, data has proven to be effective to describe national trends for this health event. Our study indicates that the public health burden and economic impact of prevention and control measures can be monitored through hospital discharge surveillance.

Reported measures of hygiene and incidence rates for hospital-acquired diarrhea in 31 French pediatric wards: is there any relationship?

OBJECTIVE

To investigate the relationship between hygienic measures reported for the prevention of hospital-acquired diarrhea and incidence rates of hospital-acquired diarrhea.

DESIGN

A survey of hospital-acquired diarrhea was conducted between January 1 and March 31, 1999. Multivariate analysis of reported measures of hygiene according to the observed incidence rates of hospital-acquired diarrhea was performed.

SETTING

Thirty-one pediatric or neonatal wards located in hospitals in the southeast of France, selected as a convenience sample of wards volunteering to participate.

PATIENTS

A total of 6,726 children younger than 5 years.

RESULTS

The overall incidence rate of hospital-acquired diarrhea was 3.6%. Rotavirus was responsible for 69% of the cases of hospital-acquired diarrhea. Among the hygienic measures reported by the wards for preventing hospital-acquired diarrhea were using a single room or cohorting (77.4%), washing hands (83.9%), wearing gowns (80.6%), and wearing disposable single-use gloves for diapering a patient (51.6%). By multivariate analysis, the variables statistically associated with a lower incidence of hospital-acquired diarrhea were restricting the patient's mobility outside his or her room, keeping the patient's door closed, and having fewer than 20 beds in the ward, with adjusted odds ratios of 0.34 (95% confidence interval [CI95], 0.18 to 0.65), 0.33 (CI95, 0.23 to 0.47), and 0.42 (CI95 0.30 to 0.60), respectively.

CONCLUSION

Simple preventive measures can decrease the rate of hospital-acquired diarrhea in pediatric wards.

Histologic distribution of fatal rotaviral pneumonitis: an immunohistochemical and RT in situ PCR analysis

Rotaviral infection is a common cause of gastroenteritis and pharyngitis; to our knowledge, infection has not been associated with severe pneumonia. We report on two cases of fatal pneumonitis in 49-and 54-year-old men; the latter was on long-term steroid treatment of multiple sclerosis. In the latter case, the histologic examination after a several week history of symptoms showed severe organizing interstitital pneumonitis and necrotizing bronchiolitis with extensive squamous metaplasia. The other case, which was fatal several days after the onset of symptoms, showed marked septal capillaritis with denudement of the alveolar pneumocytes, extravascated red blood cells, and intravascular thrombi formation. In each case, rotaviral RNA was localized by reverse transcription (RT) in situ PCR to the endothelial cells of the alveolar capillaries, macrophages, and pneumocytes as well as, in the second case, to the squamous metaplastic cells. Immunohistochemical analysis for the virus demonstrated an equivalent histologic distribution. It is concluded that rotaviral infection can lead to fatal pneumonitis and that the mechanism of this complication is centered on a diffuse septal endothelialitis with concomitant tissue damage.

International variation in disease burden of rotavirus gastroenteritis in children with community- and nosocomially acquired infection

BACKGROUND

The great impact of rotavirus disease on morbidity and medical health care costs in industrialized countries together with the withdrawal of the live oral rotavirus vaccine have made a reassessment of rotavirus gastroenteritis necessary. Such a reassessment should provide sufficient data for developing alternative disease prevention strategies and for allocating resources efficiently.

OBJECTIVES

To compare characteristics and management of community- and nosocomially acquired rotavirus disease in Austria, Germany and Switzerland.

PATIENTS AND METHODS

In a prospective, population-based, trinational (Austria, Germany, Switzerland), multicenter (9 cities, 10 hospitals and 30 pediatric practices) study, a total of 174 552 children months and 78 516 hospital days were evaluated. Participants were all children 4 years of age and younger, who either presented at one of the pediatric practices with community-acquired gastroenteritis, or who had acquired gastroenteritis nosocomially. From December, 1997, to May, 1998, prospective antigen testing was done by enzyme-linked immunosorbent assay, and serotyping was done by reverse transcription polymerase chain reaction. Disease severity was scored by the Vesikari severity scale.

RESULTS

Rotavirus was detected in 29.5, 27 and 37.5% of children with community-acquired gastroenteritis and in 57, 69 and 49% of children with nosocomial gastroenteritis in Austria, Germany and Switzerland, respectively. Severity of community-acquired rotavirus gastroenteritis was more pronounced in Austria (median severity score, 11) than in Germany (median score, 9) or Switzerland (median score, 10). However, only 2% of Austrian and Swiss children compared with 12% of German children presented to their pediatricians more than four times. Nosocomially acquired rotavirus gastroenteritis was mildest in Austria but occurred within the shortest median duration of hospitalization (4 days vs. 5 and 7 in Germany and Switzerland, respectively). In a multivariant analysis age, family size, day care, breast-feeding and nationality were not predictive factors for enhanced risk to contract rotavirus infection. Alimentation was changed frequently; diet was used between 23 and 83%; special formulas were used between 10 and 57%.

CONCLUSION

The cumulative experience from three European countries suggest that rotavirus is an important cause of diarrhea in Central Europe, but significant local differences clearly demonstrate the need for obtaining national data as a reliable basis for control and prevention of the disease.

Histologic distribution of fatal rotaviral infection: an immunohistochemical and reverse transcriptase in situ polymerase chain reaction analysis

Rotaviral infection is the most common cause of gastroenteritis in young children. Although rotavirus infection has a high morbidity and mortality rate in animals, in most cases in the United States the disease appears to be self-limited in humans. We report on 2 cases of fatal rotaviral infection in a 1 year old and a 4 year old. In each case, the illness showed a rapid systemic course dominated by cardiac and central nervous system involvement; in one case, rotaviral infection was documented by stool culture. Viral RNA was localized by reverse transcriptase in situ polymerase chain reaction to the mucosal cells of the small and large intestine and to many other tissues, including the heart and central nervous system, where it was noted in the endothelial cells of the microvasculature. Immunohistochemical analysis for the virus showed an identical histologic distribution in the intestinal epithelial cells and the systemic microvasculature. It is concluded that rotaviral infection can lead to a fatal disseminated infection in humans and the mechanism of this complication is based on a diffuse endothelialitis and concomitant tissue damage.

Three-year study to assess human enteric viruses in shellfish

The main pathogenic enteric viruses able to persist in the environment, such as hepatitis A virus (HAV), Norwalk-like virus (NLV), enterovirus (EV), rotavirus (RV), and astrovirus (AV), were detected by reverse transcription-PCR and hybridization in shellfish during a 3-year study. Oyster samples (n = 108), occasionally containing bacteria, were less frequently contaminated, showing positivity for AV (17%), NLV (23%), EV (19%), and RV (27%), whereas mussel samples, collected in areas routinely impacted by human sewage, were more highly contaminated: AV (50%), HAV (13%), NLV (35%), EV (45%), and RV (52%). Sequences obtained from HAV and NLV amplicons showed a great variety of strains, especially for NLV (strains close to Mexico, Snow Mountain Agent, or Norwalk virus). Viral contamination was mainly observed during winter months, although there were some seasonal differences among the viruses. This first study of virus detection over a fairly long period of time suggests that routine analysis of shellfish by a molecular technique is feasible.

Epidemiology of rotavirus infection in Thailand

Rotavirus is a major cause of acute severe diarrhea in children worldwide and an important cause of death among young children in developing countries. Group A rotaviruses are antigenically complex and multiple serotypes infect humans. Reassortant rotavirus vaccines are now available which offer protection against severe illness caused by rotavirus serotypes G1-4. Before vaccines are introduced into target populations, it is necessary to establish the baseline data of the epidemiology of rotavirus infection in those countries. The purpose of the present study is to provide information related to the epidemiology of rotavirus infection in Thailand. All rotavirus studies performed in Thailand were found through Medline and Thai Index Medicus searches. A total of 26 of the most relevant studies published in international and national journals are reviewed. Most studies reported that the prevalence of rotavirus infection in Thailand was 27-34%, although a few studies have reported a prevalence above this range. The peak seasonal distribution of rotavirus infection among children hospitalized with diarrhea in Thailand was seen in the dry cool seasons: October to February. The prevalence of rotavirus infection was most frequently found in children aged 6-11 months up to 2 years. G1 was the most prevalent serotype in Thailand, followed by G2, G4 and G3, respectively. At least three G serotypes, mostly G1, G2 and G4, are seen to coexist in Thailand each epidemic year and in some studies all four G-serotypes were reported in the same epidemics. In a 1996-1997 study, G9 was the third prevailing serotype after G1 and G2, respectively. These results indicate that rotavirus epidemics occur in Thailand every year and children are the most affected population. In Thailand, although G1-G4 have been reported, G1 is the most prevalent serotype in each epidemic and G9 is becoming increasingly common.

[Anti-rotavirus vaccinations]

Rotavirus is the most common cause of severe acute diarrhea, responsible for 30 to 40 deaths of children each year in France. In order to decrease both mortality and morbidity, vaccines have been designed first from attenuated bovine strains, then from monovalent simian strains, and more recently from reassortant rhesus strains. The live tetravalent human-rhesus reassortant vaccine (RRT-TV) has been shown to be protective in the United States, Finland, and Venezuela despite different environments, in prospective double-blind studies. This vaccine, as the natural infection, decreases by 50% the risk of acute rotavirus diarrhea and by 70 to 100% the risk of severe diarrhea with dehydration. At the present time, its cost limits its use to developed countries. It was put on the market in the United States in October 1998. The challenge is now to make it available in developing countries.

Seasonality and diversity of Group A rotaviruses in Europe

Group A rotaviruses are a major cause of severe gastroenteritis in children under 4 y of age worldwide. Group A rotaviruses have been identified in many animal and bird species, they are antigenically complex, and multiple serotypes infect humans. Re-assortant rotavirus vaccines are now available which confer protection against severe illness due to rotavirus serotypes G1-4. Before vaccines are introduced it is necessary to establish the diversity of rotavirus in the target population to ensure efficacy and to establish a baseline for future surveillance strategies. The purpose of this review is to describe our current knowledge of the diversity of rotaviruses across Europe. Since multinational studies with standardized methodology have not been performed, this review is based on the available published studies. In Europe, more than 90% of Group A rotavirus strains that have been typed are of serotypes G1-4, with an average 8% of non-G1-4 strains in published studies. The percentage of non-typeable strains may fluctuate from one year to another, and has been as high as 18% in one study in Great Britain, indicating the need for a more systematic study. Group A rotavirus infection typically occurs as a winter peak in the European countries studied. Comparison of seasonality data from national laboratory surveillance systems showed seasonal differences, with the annual rotavirus peak occurring first in Spain, usually in December, followed by France in February, and ending in Northern Europe in England and Wales in February or March, and the Netherlands and Finland in March.